Chemical fire-extinguishing apparatus.



J. R. HAMILTON.

CHEMICAL FIRE EXTINGWSHING APPARATUS.

APPLICATION HLED AUGMI, 1915- Patented Apr. 30, 1918.

3 SHEETSSHEET I J. R. HAMILTON. CHEMICAL FIRE ixrmsmsnmc APPARATUS.

APPLICATION HLED AUG.4. 1915- Patented Apr. 30, 1918.

3 SHEETS-SHEET 3.

ATTORNEY UNITED STATES PATENT OFFICE.

YORK, ABSIGNOR '10 SYPHO-CHEMICAL DN-ON-HUDSON, NEW YORK, A CORPO-CHEMIGAL FIRE-EXTINGUISHING APPARATUS.

To all whom it may concern.-

Bc'it' known that I, JOHN R. HAMILTON, of Yonkers, county ofWestchester, State of; New York, have made certain new and usefulInventions Relating to Chemical Fire-Extinguishing Apparatus, of whichthe followng is a specification, taken in connection with theaccompanying drawin$, which form part of the same.

his invention relates especially to fire extinguishing apparatus'inwhich the distributing system may comprise automatic or otherdistributing devices and in which a chemical rmixing tank may be used tosupply supplemental extinguishing liquid to t e system. The mixingdevices ating with the tank may comprise a primary or tarting chemicalchamber having a dischal'ge connection through which the chemi: caltends to discharge, but which may be provided with a trapped or otherretainin portion in which a mercury or other liquid may be normally heldon the emergency opthus releasing the seal restraining device until itis withdrawn oration of'the system, primary charge of acid or otherchemical which is discharged into the tank to generate the highemergency pressure therein. Supplemental pressure maintaining devicesmay be used to preferably maintain the einergency discharge pressuresubstantially constant and these devices may comprise a supplementalchemical feeding chamber and connected pressure governing chamber abovebetween which a charge of mercury may be transferred by the tankpressure to act as an automatic plunger and feed additional acid intothe tank whenever the tank pressure decreases below the predeterminedamount.

In thenccom anying drawings showing in a somewhat diagrammatic Wayillustrative embodiments of this invention- Figure 1 is a verticalsection showing one form of apparatus.

Fig. 2 shows a modified construction.

Fig. 3 shows another embodiment.

Fig. 4 is a detail section thereof showing the parts in anotherposition; and

Fig. 5 shows still another embodiment of the invention.

In the illustrative embodiment of the invention shown in Fig. 1 thedistributing system, which may be of any desired form Specification ofLetters Patent.

Application filed August 4,

Patented Apr. so, 1918. 1915, Serial No. 48,586.

and arrangement, may comprise a supply pipe, such as 3, with which areconnected -one or more distributin lines 6 having any "suitabledistributing evices, such as the automatic sprinkler heads 7, arran edat suitable oints throughout the building. The distributing s stem ispreferably normally charged wit suitable extinguishing liquid, such, forexample, as a suitable nonfreezing solution which is normally kept atsufficient pressure to dischar e from the distributing devices by asuitable priming actuating tank, such as 32, extending upward, so thatthe non-freezing or other extin ish-- ing liquid 33 h'as'sufiicient headto disc 'ar e from the operating emergency devices. 1':

case non-freezing solution is used in the sgl tem a check valve, such as4, is prefer arranged at the lower portion of the supply pipe which maybe connected with a supplemental supply of extinguishin liquid whichmay, if desired, comprise a c emical pressure tank such as the chemicalmixing tank 1 into which extends the suppl connection 2 communicatingwith the supp y pipe 3. If desired, a suitable venting device such asthe automatically closing ball check 5, may be arranged he ow the checkvalve 4 in which case it is sometimes desirable to have an equalizingopening, vent 60 between the supply connection and the upper part of themixing tank which may, if desired, be filled with an extinguish? ingliquid having in solution a pressure generating chemical, such,

the ordinary carbonate extinguishing-liq? uid 8.

may be arranged. incoiiperation with the mixing tank and may comprise astarting device adapted under fire emergency conditions to dischargeintothe tank a millcient quantity of chemical to generate in connectionwith the chemical charge already such as the pin hole 1 Any suitablechemic l mixmg g;

for instance an through the m the upper part a removable cover 15, ii.desired. This starting charge normally tends to discharge into themixing tank through a discharge connection which may comprise the trap27 and the discharge pipe 30 extending through the open throat 31 of thecasing, a suitable equaizing opening 19 being arranged in the top of thechamber to iacilitate this discharge. A suitable restraining device maycoiiperate with the discharge connection so as to normally restrain thedischarge of the starting chemical therethrough and for this purpose itis desirable to employ a liquid seal or plug 28 of such character andcomposition as not to be undesirablyacted on by the starting chemicaland, to effectively restrain its discharge, mercury being a convenientand effective liquid seal for this purpose when the starting charge isof sulfuric acid, for instance.

This restrainin mercury seal or plu may be normally be d in the positionin'icated in Fig.1 bythe fluid pressure in the system as by.allpwingthis premure to be exerted actuating pressure pipe 9 on theactuatin chamber 10 which contains a charge 11 o mercury so that underthese conditions the normal pressure in the sys temforces part of thismercury up through the actuatingv transfer pipe 13, the lower part 12 ofwhich extends adjacent the bottom of the chamber so asto maintain. anefl'ective restraining liquid seal or plug 28 in the. dischargeconnection which is forced upward in. the trap sufliciently to sustainthe pressure caused by the starting charge 18 above. Under emergencyconditions when one or more of the distributing devices opens and liquidfrom the system is discharged therethrough the pressure exerted in theactuating chamber is correspondingly decreased and the mercury from thetransfer pipe and trap retintcrs the actuating chamber so as to allow afree passage through the tra. ped discharge connection through. which tc said or other chemical charge 18 uickly flows into the mixing tank, avent ng passage 26 being arranged of this discharge connection m case itis desired to prevent" siphon action, although otherwise this passage isunnecessary. This rapidly generates the ,of thegas in'the upper partemergency chemical gas pressure within the tankand forces the.extinguishing liquid up through the supply connection so as to close theventing device li and open the check valve; 4 so as: to supply liquid tothe distributin system for high pressure dis charge rom theoperatingdistributing devices. Under these conditions the pressure of the mixingtank and connected casing equals or exceeds the pressure .in'tbellsupplypi e 3 so that the mercury remains within t e actuating chamber and hasno tendshcy whatever to .25 which may be normally close sure falls sothat through suitable co interfere with the flow of any remaining partof the starting charge 18 into t e tank. Any suitable means may be empoyed to maintain the desired high emergency pressure in the mixing tankwhile the char e of oxtingu ishing liquid is being discharged rom thesystem and preferably suitable chemical mixing devices are arranged inconnection with the tank to maintain this emergency discharge pressuresubstantially constant throughout at least the greater part of thedischarge from the tank. Fig. 1 illustrates one of a number of suitablesupplemental chemical mixing devices which may be used for this purposein connection with the starting devices shown in this form of theinvention and as therein indicated a sup"3 plemcntal chemical or acidholder 21 may arranged or formed as one chamber of the multiple receiver16 within the casing14 and preferably provided with the upper vent oropening 20 sov as to normally contain a suitable supplemental charge 22of pressure generating chemical or acid adapted to react with thechemical 8 in the mixing tank below. Under emergency conditions thissupplemental chemical charge is adapted to be transferred to thesupplemental chemical or acid feeding chamber 23 as by passing throughthe holder discharge passage or pipe by any convenient device, such forinstance as the seal or plug 24 of suitable liquid, such for example, asmercury, which may partly fill the feeding chamber under normalconditions. Under emergency conditions when the high emergency pressureis chemically generated in the tank this mercury seal 24 may be largelyor partly forced out of the feeding chamber as througha transfer pipe sothat the fiower end of the holderdis charge pipe 25 is thus uncoveredand the supplemental charge of chemical or acid '22 thereupon bodilydescends into the supchamber 23 which is 0f 11 plernental feeding suchsize as to be thus substantially filled with this supplemental chemicalcharge which is subsequently gradually fed into the mixing t'ankwhenever the emergencg preg- P m ing governing means or devices the, eergency discharge pressure may be maintained substantially constant inthe mixing tank. and connected distributing system. These governingdevices may "comprise a pressure governing chamberfsuch as 36, arrangedat such height above the feeding chamber as to produce a gravitypressure head of the mercury or other liquid seal substantially equal tothe cmergemy discharge pressureinthe tank This pressure govcrniugchamberis preferably made of such capacity so thatgctbor with the governingtransfer i aas.

conne ting it with tbecontrol chambemthe'w mercurycharge in these partssubstantially fills this governing chamber when the mercury is forced upinto it to such extent as to first uncover the lower end of the holderdischarge pipe. Any suitable over-pressure control devices may bearranged in connection with the pressure overning chamber so aspreferably to consi erably increase the pressure orliquid resistanceexerted against any further passage of the mercury from the feedingchamber into the governing chamber and this may be conveniently effectedby having a relatively small area over-pressure reservoir pi e 38connected to the pressuregoverning e amber so that the entrance of anyfurther mercury into this governing chamber forces mercury. into thisover-pressure reservoir pipe an causes such a rapid rise therein as toproduce a correspondingly rapid increase in the gravity head thusexerted and, correspondingly minimize the danger of: the mercurysealpressure device being rendered ineffective. Under emergency conditionsafter the mercury has been forced up to substantially fill thepressuregoverniiig chamber 36 and after the acid 22 has descended intothe supplemental feeding chamber to substantially fill the same above ithe thin layer of mercury remaining in the bottom of this chamber anydecrease in the gas pressure within the mixing tank causes acorresponding descent of the mercury fromv the governing chamber intothe" supplemental feeding chamber 24 so as to force a correspondingamount of the acid over the discharge "Ii 34 of this feeding chamberdown into t e acid discharge pipe 30 c0mmunicating "with the mixingtank. This quickly generates additional pressure in the tank and tendsto force the mercury back from the feedin chamber into the pressuregoverning chem )er. The chemical or acid is thus gradually fed= from thefeeding chamber in'zi series-of relatively small increments whenever theemergency pressure begins to fall in the tank and by making thesupplemental feedin chamber and thepressure overnihgzcham lier of suchproportions as to e relatively fiat or shallow the emerencypressure'within the mixing tank'may is regulated quite closely. Byarranging the pressure governing chamberseVeraI feet above thesupplemental feeding chamber so as to secure a'mercury pressure head of50 to 100 pounds or so per square inch which is sustained underemergency conditions by the gas pressure within the mixing tank any decrease in this gas pressure of a few pounds such as would allow thelevel of the mercury in the pressure governing chamber to fall from thetop of that chamber to about the point indicated bythe dotted line 37would cause a'corresponding volume of mercury to flow from the governingchamber into the feeding eh'amberwhere it would act as a feeding plungeror piston to feed a correspending volume of acid or pressure generatingchemical into the mixing tank. Under some conditions it is desirable tolimit the rate at which acid is discharged from the supplemental feedingchamber so as to prevent an undesirable sudden rise of pressure in thetank and for this purpose the effective area of the governing transferpipe 35 may be ropcrly proportioned or controlled prefera 1y byinterposing therein a throttling check valve, such as 75, which isadapted to be held down on its seat 76 when the mercury descends duringone of these feeding impulses, so that all the mercury is then forced topass through the restricted throttling passage 79 in this valve. Thevalve is, however, allowed to rise against the action of the lightspring 78 shown above it so that the valve engages suitable stops orguides 77 so as to allow the free upward passage of the mercury duringthe start of the emergency operation of the device, for instance, thesize 0 these parts being somewhat exaggerated in Fig. 1 for greatercleerness.

A" somewhat similar starting device is shown in Fig. 2 as comprising thestarting chamber 17 containing the charge 18 of starting chemical oracid charge into the mixin tank 1 through the discharge connection 6%preferably comprise ing the trap 68. A restraining device automaticallyactuated on the emergency condition of the distributingsystem isarranged to cooperate with this discharge connection and may comprisethe liquid or mercury seal 28 normally forced up the transfer pipe 13from the actuatingchamber 10 by the pressure exerted on the uppersurface of the merwhich tends to discury ll in this actuating chamber bya suitable actuating connection or pipe BO which may normallycommunicate with the priming actuating tank 32 or other upper part ofthe distributing system so as to receive liquid 33 therefrom. Asindicated in Fig. 2 this charge of extinguishing liquid'in thedistributing system may in some cases be the same as the chemical charge8 in the mixin tank and thisarrangement may be efiected by keepingnormally a suflicient air p ssure in the mixing tank 1 so as to force"extinguishing liquid 11 to the top of the ystem Where a sight g ass 81indicates its normal position. Under fire emergency conditions when oneof the distributin devices comes into operation the liquid is dischargedfrom the system and suflicient suction or pressure reduction is thusdeveloped in the substantially closed upper part of the distributingsystem with which the suction ac? hinting pipe 80 communicates, so thata sue t-ion impulse of a numbcrof pounds or so is thus exerted on theactuating chamber 10 and the mercury seal 28 is thus quickly withdrawnfrom the trap 68 and the starting charge 18 thus quickly flows over thelip 69 and through the discharge pipe 67 without the necessary action ofany solid movin parts. oped in the tank causes a flow of liquid through.the supply ipe 3, the inertia and friction effects of the hilllld inthese pipes being sufiicient to make t e air pressure in the tank exceedfor a time at least after the distributing devices begin to operate, thepressure initially caused by the actuating pipe 80 in the actuatingchamber 10 so that b making the. area of the discharge pipe 6 ample thecertain discharge of all of the starting charge 18 may be effected. Byarranging the lower end 81 of the suction actuating pipe 80 in suchposition that it dips into the mercury 11 in the tank before therelatively large area transfer pipe 13 is free from mercury, aneffective mercury seal is always maintained between the gas s ace of themixing tank and the upper part 0 the system.

By thus quickly discharging a predetermined amount of acid or pressuregenerating chemical 18 into the mixing tankthe desired emergencypressure can be developed therein and this pressure can thereafter bemaintained substantially constant by any suitable pressure maintainingdevices of a chemical mixing character, for instance, the supplementalchemical or acid chamber 70 may for this purpose be arranged within theeasing 14. and may be partly filled with a supplemcn al charge 71 ofacid or other Pressure" producing hemi al which is radually dis chargedthrough a siphon disc arge pipe 72,

the lower end 7 3 of which is adjacent the bottom of the supplementalchamber, whenever the emergency gas pressure in the tank falls. When thesystem comes into emergen operation the air nd gas in the tank pass intothis discharge spout 72 so as to develop the same-emergent: ressurewithin this supplemental cham er and then whenthe pressure in the tankfalls a few pounds this pres sure within the chamber is suflicient toforce out an increment of the acid or chemical charge which passes outof the spout72 into the discharge pipe 74 communicating with the tank.Thus additional gas pressure is chemically created and a substantiallyconstant emergency pressure can be maintained throughout a large part atleast of the discharge of the extinguishing liquid from the tank.

Another suitable arrangement is'indicated in Fig. 3 as preferably thoughnot necessarily comprising a wet pipe distributing system which may becharged with non-freezing exting-uishiug liquid 33 separated by thecheck valve 4 from the supply connection 53 communicatingwith the bottomof the chemical mixing tank 39. This tank may contain a charge 40 ofcarbonate extinguishing liquid or other suitable pressure producingchemi- The chemical pressure then deve the mercury cal and the startingdevice may e06 crate therewith so as to produce the qgasired c emicalpressure under emergenc, conditions. This starting device'may comprisethe primary chemical or acid chamber 34 containing a charge 35 ofsulfuric acid or other suitable chemical which tends to flow through thedischarge pipe 138 into the mixing tank. This discharge pipe orconnection may comprise the trap 136 in which may be located arestrainin device such as the mercury seal 42 normal y forced u throughthe tra fer pipe 13, the lower en 12 ofwhich dips to charge 11 in theactuating chamber 10. T e actuating ressure pi e 9 may connect with anysuitable part 0 the dis tributing system so as to transmit the pressureof the air or liquid therein to the tank and force the mercury seal intoits restraining position indicated in Fig. 3. Under emergencyconditions, however, this ressur on the actuating tank is decreased suciently so that the mercury seal is withdrawn from the discharge pipeand the acid charge 35 quickly flows up overthe siphonpbrtion 137 of thepipe into the mixing tank, the equalizing pipe 4l allowing this flow totake place without lnterruption.

Any suitable pressure maintaining devicemay be used in connection withthis form of the apparatus so as to supply additional amounts of acid orpressure producing chemical to the tank whenever the gas ressure .jallstherein nd as indicated the c emical tainer 52 pivoted, for instance,about they pivots 46 in the casing 43 connected to the tank through thethroat 51. The lower part of this casing 43 is adapted to containmercury or other sustaining liquid 49 in which the container is more orloss floating under emergency conditions and the casing is connected bythe governing transfer pipe 50 with the governing pressure chamber 86 sothat on decrease of the gas pressure in the tank more mercury flows intothe chamber so as to lift and tilt the acid container and discharge partof its contents through the spout 47 into the tank as indicated in Fig.4. If desired the pressure governing chamber 36 may be provided with anever-pressure reservoir pipe 38 so as to take care of excess pressures.If desired also part of the mercury charge for the casing 43 may becontained in a weighting compartment 44 on the container so that theparts, under normalinactive condition of the system, are in the positionindicated in Fig. 3.- When, however, the system comes into emergencyoperation the increase of gas pressure in the 3 and the distributingline 6 having tank drives the mercury up into the pressure governingchamber 36 so that the container tilts downward away from its pivot anda large part at least of the supplemental charge 45 of mercur isdischarged from this compartment into the casing 43 so as to increasethe amount of mercury therein.

, Another arrangement is shown in Fig. 5 as preferably comprising a wetpipe distributing system comprising the supply pipe any suitabledistributing devices or sprinkler heads 7 The check valvc l may bearranged to maintain the desired non-freezing or other extinguishingliquid in the system under'normal conditions and if desired anautomatically closing ball check venting device 5 may-be arranged belowthe valve between it and the supply connection 2 extending into thecarbonate or other chemical charge 8 in the mixing tank 1. A pin-holeequalizing aperture 60 is preferably ar ranged in this connection as inthe case of the Fig. 1 arrangement. The acid or coo'peratin pressuregenerating chemical 129 maylie contained in a casing or chamber Hi7mounted on the tank and provided with a harge aperture 131 nor'mallyheld closed-by the control valve 130. This valve may be mountedon thestem 128 secured by the nutsor washers 124 to the flexible metalor othercontrol diaphragm 125 mounted within the cover 126 of the casing. A

J sprin 123 is arranged above this diaphragm and t e adjusting nut 122may beadjusted above'this spring so as to regulate the pres sure withinthe chamber which will tend to keep the diaphragm closed. Under normalinoperative conditions where the tank is under atmosphericor otherpressure less than the usual high emergency discharge pres sure thisdiaphragm valve tends to open and a suitable restraining device is usedin connection therewith to normally keep it closed until the s stemcomes into emergenc operation. mercury float restraining evice f may beused for this purpose and may comprise the float 116 of any suitablematerial arranged within the float chamber 114 and pivoted by the pin117 to the restraining levcr 118. The other end of this lever ispivotedby the pin 120 to the bracket 121 on the casing cover and undernormal conditions the lever is held up against the underside of the,head- 119 on the valve stem by the mercury 1 15 around the float 116.This mercury is under normal conditions forced up from the actuatingchamber 10 by the action of the actuating pressure transfer pipe 9 whichtransmits the liquid or other pressure from the system so that it actson top of the mercury 11 in this chamber and forces it into the end 12of the transfer ipe 13 so as to raise it'into the float chain er toabout the extent indicated. This powerfsm straining closing action isexerted on the valve stem and valve which is thus kept tightly closedunder normal conditions. When, however, one of the distributing devicesopens and allows the pressurein the system to fall the mercury is nolonger held up in the float chamber and its fall allows the floatand'connected control or restraining lever 118 to descend so that thecontrol spring 123 quickly opens the valve 130 and allows SllfilClBIlbacid to run into the tank to quicklydevelo the desired emergencypressure therein. his pressure is transmitted through the equalizingpipe 141 to the casing below the diaphragm so that as soon as thepredetermined emergency discharge pressure is reached the diaphragm ispushed upward against its spring and tightly closes the control valve130. Any decrease in this amount of pressure above the atmosphericpressure which is actin on the upper side of the diaphragm quic 1ycauses a corresponding supplemental flow of acid so that as long as anyof the acid char e remains the tank pressure is kept at su stantiallythe predetermined emergency pressure. Under these emergenc conditionsalso the emergency ressure rom the tank and equalizing pipe 141 istransmitted through the pipe 142 to the to of the closed float chamber114 so that t e mercury tends to descend into the actuating tank 10 andremain there so as to have no further action on the float 116.

. It'is of course desirable to form the acid containers and cooperatindgtrapped portions of the communicating ischarge passages with which themercury and acid coilperate of some suitable material which is notundesirably acted upon by these substances. If desired, glass orchemical earthenware may be used for these parts of the apparatus andalso preferably for the cooperating actuating overnin chambers, althoughacid does not ave such extended or continued contact therewith. In someinstances, however, a suitable protective coating, such as bakelite, orother resistant coating preferably of a somewhat elastic-resilientcharacter may as indicated in Fig. 2 be applied to cast iron or othersuitable metal chambers and connected pipes having proper form so thatthe acid and mercur are prevented from having undesirable dlrect contactwith the metal.

This invention has been described in 0on nection with a number ofillustrative embodiments, forms, arrangements, materials,

PIOPOI'LIOIIS, sizes and arts of the apparatus,

to the details of whlch disclosure the invention is not of course to belimited, since what is claimed as new and what is desired 4 i to besecured b Letters Patent is set forth in the appends claims:

1. In automatic fire extinguishing appa= ributing devices,

ratus, a distributing system comprising disa supplemental supply ofextinguishing liquid connectcd to said system and comprising a chemicalmixing tank charged with carbonate liquid and cooperating mixing devicesincluding a startln device comprising a starting charge of am andcommunicatlng with said tank, a restraining device coiiperating withsaidstartingdevlce, [an actuating pressure pipe connecting saidrcstrainin device and said distributmg system to e ect the discharge ofsaid acid into said tankto generate emerfire emergency gei c'y pressurein 'saidtftanlc comprising a cup viemehtal cid 'T edin chamber having ach massage oonnnunicating with Suid1iifihk,"i a" governing transfer ipecon- 045 sai r-ceding c l p napressuregevemm chamber conchamber, aliover pressure reservoir pipe connected to said governing transfer pipeand extending above said pressure governing chamber, a charge of mercuryn'ormally located in said feedingchamber, a supplemental charge of acidin said'feediiagchamber in contact with said mercury, sai pressuregoverning chamber bein located at a height above said feeding chal berproducing agravity head corresponding with the emergency pressure insaid tank to effect the forcing of said mcron into said pressuregoverning chamber nu. erlemergency conditions to feed the acidffiOfiiBffi-id feeding chamber into said tank by the iaegersee n of themercury from said pressure 9YQiug chamber Whenever the taifiiipfssurefalls below the normal emergeneypressui'e. a

-2'. ,In aut matic fi e, extinguishi ap amt fili fine eye am empr smextinguishing liquid connected to said sys tem d "ihiiiismg a chemicalmixing tank a ith carbonate liquid and cooperuting min ngdevices'including a starting device Ito;eficctithe'discharge of said acid intosaid tank to generate the. emergency pressure therein under fireemergency conditions, and means to maintain the emergency pressure in'sa'id tank com rising a supplemental acid feeding chamber avingadischa'rge passage communicating with'said tank, a governm traus-ferpapa connected to the lower ingfchamber, a pressure governing chamberconnected tosaid governingtransfer pipe and located above said feedingchamber, an over-pressure reservoir pipe; connected. Lto said governingtransfer pipe and extending above said pressure gov- I ernrng chamber, acharge of mercury normlly located in saidteeding chamben'a-sup- 'plcmental' charge of acidin said feeding transfer iipeand said feeding asu'ppemental supply of.

I chamber in contact with said mercury, said pressure governin chamberbeing Located at a height above sai fceding'chambcr producing agravityhcad corresponding with the emergency pressure in said tank toeffect the forcing of said mercury into saidpressurc governing chamberunder emergenc conditions to feed the acid from said fieding chamber,into said tank byvthe plunger action of the mercury from said pressuregov er in chamber whenever the tankpressure fa ls clow the normalemergency pressure.

3. In automatic fire extinguishing ratus, tributing devices, asupplemental supply of extinguishing liquid cohnected to said system andcomprising a chemical mix tank charged with carbonate liquid and coiiperating mixing devices including a starting device to c'ffectthe'dischargcof saidacid into said tanigtogcnerateiemergency pressiirc therein underfire emergency conditions,

and means to maintain the emergency pres-- sure in said tank comprisinga suppiemental acid feeding chamber having a discharge passagecommunicating with said tank, a governing transfer pipe connected to thelower part of said feeding chamber, a pres sure governing chamberconnected to said governing transfer pipe and located above chamber, acharge of mercury normally located in said feeding chamber, asupplemental charge of acid in said feed ing chamber in contact withsaidmercury, said pressure governing chamber being located at a heightabove said feeding chamber produciuga gravity head corresponding withthe emergency pressurei'n saidtanl; to effect the forcing of "saidmercuryinto said pressure governmg chamber under emergency conditions tofeed the acid from said feeding chamber intc said tank by uie'pluager'action of the mercury from said pressure governing chamberWheneverthe tank pres sure falls below the normal emergency sure. 1 y i4.'In fire extinguishing apparatus, supplemental supply of extinguishingiiquld adapted to be connected to the distributing system and comprisinga chemical mixing ip?- a distributing system comprising istank chargedwith chemical and means to a depending diswhich said discharge pipe pro.aeaiiig and extending above said pressure governing chamber, a chargeof mercury normally located in said feedin chamberand closing thedepending end of said discharge pipe, a supplemental charge of acid incontact with said mercury in said feeding chamber, said pressuregoverning chamber being of such size as to be substantially filled withthe mercury forced thercinto when the emergency ressure is firstdeveloped and being located at a height above said feeding chamberproducing a gravity head correspondin with the emergency pressure insaid tan to effect the feeding of said supplemental acid charge fromsaid feeding chamber into said tank by the plunger action of the mercuryfrom said pressure governing chamber when the'tank pressure fallsbelowthe normal emergency pressure.

5. In fire extinguishing apparatus, a sup plemental supply ofextinguishing liquid adapted to be connected to the distributing systemand comprising a chemical mixing tank charged with chemical and means tocause an emergency pressure in said tank, and means to maintain theemergency pressure in said tank com rising a supplemental acid feedingchamber aving a discharge passage communicating with said tank, agoverning transfer pipe connected to the lower part of said feedingchamber, a pressure governin chamber connected to said overning trans erpipe and located above said feeding chamber, an over-pressure reservoirpipe connected to said governing transfer pipe and extending above saidpressure governing chamber, a charge of mercury normally located in saidfeeding chamber, a supple mental charge of acid in contact with saidmercury in said feeding chamber, said pressure governing chamber beingof such size as to be substantially filled with the mercury forcedthercinlo when the cn'iergency pres sure is first developed and beinglocated at a height above said feeding chamber producing a gravity headcorresponding with the emergency pressure in said tank to effect thefeeding of said supplemental acid charge from said feeding chamber intosaid tank by the plunger action of the mercury from said pressuregovernin chamber when the tank pressure falls below the normal emergencypressure.

6.In'fire extinguishing apparatus, a supplemental supply ofextinguishing liquid adapted to be connected to the distributing systemand comprising a chemical mixing tank charged with chemical and means tocause an emergency pressure in said tank, and means to maintain theemergency pressure in said tank comprising a supplemental acid feedingchamber "having a discharge passage communicating with said tank, a

governing transfer pilpe connected to the lower part of saidfee mgchamber, apressure governing chamber connected to said governingtransfer ipe and located above said feeding cham er, an over-pressurereservoir pipe connected to said governing transfer pipe and extendingabove said pressure governing chamber, a charge of mercury normallylocated in said feeding chamber, a supplemental charge of acid incontact with said mercury in said feeding chamber, said pressuregovernin chamber being located at a height above saidfeeding chamberproducing a gravity head correspondm with the emergency pressure in saidtan to effect the feeding of said sup plemental acid charge from saidfeeding chamber into said tank by the plunger action of the mercury fromsaid pressure overning chamber when the tank pressure ills below thenormal emergency pressure.

7. In fire extinguishing apparatus, a sup plemental supply ofextinguishing liquid adapted to be connected to'the distributing systemand, con'iprising a chemical mixing tank charged with chemical and meansto cause an emergency pressure in said tank, and means to maintain theemergency pressure in said tank comprisin a supplemental acid feedingchamber having a discharge passage connnunicating with said, tank, agoverning transfer pipe connected, to the lower partof said feedingchamber, a pres sure governing chamber connected to said governingtransfer pipe and located above said feeding chamber, a charge ofmercury normally located in said feeding chamber, a supplemental chargeof acidin contact with said mercur in said feeding chamber to effect thefee ing of said supplemental acid charge from said feeding chamber intosaid tank by the plunger action of the mercury from said pressuregoverning chamber when the tank pressure falls below the normalemergency pressure.

, 8. In fire-extinguishing apparatus, a dis tributing system comprisingautomatic distributing devices, a supplemental supply of extinguishingliquid connected to said system and comprising a chemical mixin pressuretank and cooperating mixing devices including a starting devicecomprising a starting acid chamber having a starting charge of chemicaltherein and connected means actuated on the emergency condition of saidsystem to discharge said starting charge'into said tank and means tomaintain the emergency pressure in said tank comprising a supplementalchemical holder formed with a depending discharge ipe, a sup lementalchemical feeding chain er into w ich said discharge pipe projects andhavin a discharge passage communicating with said located in saidfeeding chamber and closing the depending end of said discharge pipe, asupplemental charge of chemical 1n said supplemental holder and retainedtherein by said mercury, said pressure ggverning chamber bein of suchsize as to e substantially filled wit the mercury forced thereinto whensaid discharge pipe is first uncovered and being located at a heightabove said feeding chamber producing a, gravity head corresponding withthe emergency pressure in said tank to effect the forcing of saidmercury into said pressure govermn chamber under emergency conditions toal ow said suppleental charge to enter said feeding 0 amlier and besubsequently fed therefrom into said tank by the plunger action of themercury rom said pressure foverning chamber when .the tank pressure allsbelow the Inormal emergency pressure, and a check valve in saidgoverning transfer pipe automatically closing to form a restrictedpassage for said mercury into said feeding chamber.

' 9. In the extinguishing apparatus, a dis- ,tributing system comprisingautomatic dis- .tem and comprising a chemical mixin pressure tank andcoiiperatm including a starting device comprising a tributing devices, asupplemental supply of extinguishing liquid connected to said. sysmixingevices starting charge of chemical therein and connectcd means actuatedon the emergency condition of said system to discharge said startingcharge into said tank and means to maintam the emergenc pressure in saidtank comprising a supp emental'chemical holder formed'with a dependingdischargepipe, ,a supplemental chemical feeding chamber into which saiddischarge pipe projects and having a discharge passage communicatingwith said tank, a governing transfer pipe connected to the lower part ofsaid feeding chamber, a pressure governing chamber connected to saidgovernin transfer pipe and located aboye said fee mg chamber,.anover-pressure device pipe conpected to said governing transfer pipe,acnarge of mercury normally located in said feeding chamber and closingthe depending end of said d scharge pipe, a supplemental charge ofchemical in said supplemental holder and retained therein bysaid'mercury, said pres ure governing chamber being of such siz asto besubstantially fillet. -.h the m rcury forced thereinto when saiddischarge pipe is first uncovered and being locate! ata height abovesaid feeding chamber producing a gravity head corresponding with theemergency pressure in said tank to vll'cct the forcing ofsaid'mercuryinto said ressure governing chamber under emergency conditions to allowsaid supplemental charge to enter said fer Zing chamber and besubsequently fed therefrom into said tank by the plunger action of themercury from'said pressure governin chamber when the tankpressure fallsbe ow the normal emergency pressure.

10. In fire extinguishing apparatus, a d stributing system comprisingautomatic distributing devices, a supplemental supply of extinguishingliquid connected to said system and comprising a chemical mixin pressuretank and coiiperating mixing evices including a starting devicecomprising a starting charge of chemical therein and connected meansactuated on the emergency condition of said system to discharge saidstarting charge into said tank and means to maintain the emergencypressure in said tank comprising a supplemental chemical holder formedwith a depending discharge pipe, a supplemental chemical feeding chamberinto which said discharge pipe projects and having a dischar e passagecommunicatin with said ta a governing transfer pipe connected to thelower part of said feeding chamber, a pressure governing chamberconnected to said governing trans fer pipe and located above saidfeeding chamber, a charge of mercury normally located in said feedinchamber and closing the depending end 0 said dischar e pipe, asupplemental charge of chemica in said supplemental holder and retainedtherein b said mercury, said pressure governing c iamber being of suchsize as to be substantially filled with the mercury forced thereintowhen said discharge pipe is first uncovered and being located at aheight above said feeding chamber producing a gravity head correspondinwith the emergency pressure in said tan to effect the forcing of saidmercury into said pressure governin chamber under emergency conditionsto a feeding chamber and be subse uently fed therefrom into said tank byt e plunger actionof the mercur from said pressure overning chamber w enthe tank pressure alls below the normal emergency pressure.

11. In chemical pressure devices adapted for use in automatic fireextinguishing appa- Iatus, a chemical mixin tank charged with pressureproducing c emical, means to maintain t 10 pressure in said tankcomprising a supplemental chemical feeding chamber containing acooperating chemical charge having a discharge passage communicatingwith said tank and coiiperating chemical dischar ing means comprising agoverning trans er pi e connected to the lower part of said feedingchamber, a pres sure governing chamber connected. said governingtransfer pipe ,yand located above said feeding chamber, an over-pressurereser'voir pipe connected to J said governing transfe; pipe andextendm'ga bove said wres sure governing chamber, a charge of liquid ofgreater specific gravity than said chemical charge and normally locatedin said feeding chamber, said pressure governing chamber being of suchsize as to be substantially filled when the liquid is first forcedthereinto and being-located above said feed ing chamber to produce apressure corresponding with the desired pressure in said tank to effectthe forcing of said liquid into said pressure governin chamber under thedesired pressure conditlons and to eflect the feeding of chemical intosaid tank by the plunger action of the liquid from said pres suregoverning chamber when the tank pressure ails below the desired ressure.

12. In chemical pressure evices adapted for use in automatic fireextinguishing apparatus, a chemical mixing tank charged with pressureproducing chemical, means to maintain the pressure in said tankcomprising a supplemental chemical feeding chamber containing acoiiperating chemical charge having a discharge passage communicatingwith said tank and cotipcrating chemical discharging means comprising agoverning transfer pipe connected to said feeding chamber, a pressuregoverning chamber c0nneeted to said governing transfer pipe and locatedabove said feedin chamber, an overpressure device connecte to saidgoverning transfer pipe, a charge of liquid of greater specific gravitythan said chemical charge and normally located in said feeding chamber,said pressure governing chamber being located above said feeding chamberto produce a pressure corresponding with the desired pressure insaid-tank to effect the forcing of said liquid into said pressuregoverning chamber under the desired pressure conditions and to effectthe feeding of chemical into said tank by the action of the liquid fromsaid pressure governing chamber when the tank pressure falls below thedesired pressure.

13. In chemical pressure devices adapted for use in automatic fireextinguishing ap paratus, a chemical mixing tank charged with pressureproducing chemical, means to maintain the pressure iii said tankcomprising a supplemental chemical feeding chamber containing acooperating chemical charge having a discharge passage communicatingwith said tank and cooperating chemical dis charging means comprising agoverning transfer pipe connected to said feeding chamber,a pressuregoverning chamber connected to said governing transfer pipe and locatedabove said feeding chamber, a charge of liquid of greater specificgravity than said chemical charge and normally located in said feedingchamber. said pressure governing chambcrbeing located above said feedingchamber to produce a pressure corresponding with the desired pressure insaid r tank to effect the forcing of said liquid into said pressuregoverning chamber under the desired pressure conditions and to efiectthe feeding of chemical into said tank by the action of the liquid fromsaid pressure overning chamber when the tank pressure alls below thedesired pressure.

14. In automatic fire extinguishing apparatus, a distributing systemcharged with extinguishing liquid and comprising auto matic distributingdevices, a supplemental supply'of extinguishing liquid connected to saidsystem and comprising a chemical mixing tank charged with carbonateextinguishi, ing liquid and coiiperating mixing devices including astarting device comprising a starting chamber having a starting chargeof acid chemical therein and having a discharge passage communicatingwith said tank, a restraining device cotiperating with the dischargepassage of said starting device and comprising an actuating pressurepipe connecting said restraining device and said distributing system, toprevent discharge of said starting charge into said. tank under normalconditions, and to effect the discharge of said starting charge intosaid tank under lire emergency conditions to generate of sa'id startingdevice and comprising an actuating pressure pipe connecting saidrestraining device and saiddistributing systeln, to prevent dischargeofsaid starting charge into said tank under normal conditions, and toeffect the discharge of said starting charge into said tank under fireemergency conditions to generate emergency pressure therein.

16. In fire extinguishing apparatus, a distributing system comprisingdistributing (levices, a supplemental supply of extinguishing liquidconnected to saidsystem and comprising a chemical mixmg tank chargedwith extinguishing liquid and cofiperating mixing devices including astarting device comprising a starting chamber having a starting chargeof chemical therein and having a discharge passage communicating withsaid tank, a restraining device cooperating withthe discharge passage ofsaid starting device and comprising anactuatin pressure pi connectinsaid restraining evice and said" distributing system to "prevent dis-/charge of said starting chargeinto said tank under normal conditions,and to died the discharge of said starting charge into said tank underfire emergency conditions to generate emergency pressure therein.

17. In fire extinguishing apparatus a distributing system comprisingdistributing devices, asupplemental sup y of extinguishing' liquidconnected to sai system and comprising a chemical mixin tank' 'andcoiiperating mixing devices inc uding\a starting device comprising astartin chamberhaying a startin c arge of c cmical therein and having adischarge passage communicating with said tank, a-restrainmgdeviceconnected with said system and with the discharge passage of saidstarting device and comprisi' Jan actuating pressure pipe connectlng sad-restraining device and said distributing system a to recent discharge.of said startin charge into said tank under normal -e lri0n23""fll'ldt0' eiiect the dis charge of said starting charge into said tankunder fire emergency conditions to generate emergency pressure therei ii 18. In nutoltmtic fire extinguishing apparatus, a distributing systemcharged with extinguishing liquid and comprising distribiit'ing devicesincluding automatic sprinkler heads. a supplemental supply ofextinguishing liquid connected to said so stem and comprising a chemicalmixing tan charged with extinguishing liquid and cooperating mixingdevices" including a starting device cumprisin a starting chamber havinga startingc a'rge ofphenricartherein and hav in; a discharge vpassagcfarmed with 41 trap and communicatingwith said tank, a restrainingdevice connected with said starting device rind with said system andcomprising an actuating chamber and an actuatinu transfer pi econnecting said actuating; chamber and said trapi 'an actuatingpi-cssu'rt'r pipe connecting said actuating rluunhcr m1 saiddistributing system. a clnirge of heavy liquid normally forced into saidactuating transfer pipe and trapto form a restraining liquidsealpreventing discharge of said start ing charge of chemical into said tankunder normal conditions. said seal being withdrawn from said trap intosaid actuating cliamberunder (uncrgcncy conditions to effect the rapiddischarge of said starting charge into said tank togcncratc emergencypressure ther'eiu. and means to maintain the emergency pressuriin saidtank comprising a supplemental tlicmiclil charge and coiiperating meansto gradually teed said"supplemental" charm into said tank creases. I a'19. In mltomatic fire extinguishing apu'hcn the pressure thcrcindcparatus, a distributing system char with extinguishing liquid andcomprisiiig distributing devices, a supplemental supply of extinguishingliquid connected to said systeni and compris ng a chemical mixing tankcharged with extinguishing 1i aid and 00- operating mix Q g devicesinclu ing a starting device co prising a starting chamber having astarting charge ofchemical therein and having a discharge passage formedwith a trap and communicating with said tank, a restraining deviceconnected with said starting device and with said system and comprisingan actuating chamher and an actuating transfer pipe connecting saidactuating chamber and said trap an actuating pressure pipe connectingsaid actuating chamber and said distribut ing system, a charge of heavyliquid normally forced into said actuating transfer pipe and trap toform a restraining liquid seal preventing discharge of said startingcharge into said tank under normal conditions, said seal being withdrawnfrom said trap into said actuating chamber under emergency conditions toeffect the rapid discharge of said starting charge into said tank togenerate emergency pressure therein.

20. In fire extinguishing apparatus, a distributing system comprisingdistributing de vices. a supply of extinguishing liquid connected tosaid system and comprising a chemical mixing tank charged withextinguishin'g liquid and coiiperating mixing devices including astarting device comprisinga stnrtingchamber aving astarting charge ofchemical therein and having a discharge passage formed with a trap andcomnmnicating with said tank, a restraining device connected with saidstarting device and with said system and comprising an actuating,chamber and can actuating transfer pipe connecting said actuatingchamber and said trap, a charge of heavy liquid normally forced mto saidactuatin transfer pipe and trap to form a restraining liquid sealpreventing discharge of said starting charge into saidtank under normalconditions, said seal being withdrawn from said trap into said actuatingchamber under emergency conditions to effect the rapid discharge of saidstarting charge into said tank to generate emergency pressure therein.

2]. Tu fire extinguishing apparatus, a dislrilmting system comprisingdistributing derives, a supply of extinguishing liquid runnrrlrd to saidsystem and comprising a ci vl'nirful mixing tank and coiipcrating mixingdcviccs including a starting device com prising! a startingchgunbcrhaving a startlug: -lmrgc of chemical tlwrelu and having adischarge passage formed with a trap and communicating with said tank,and a resirnining drvicc connected with said starting device and withsaid systci n andcom- 1 ,aeasea prising a charge ofhcavy liquid to forma restraining liquid seal preventing discharge of said starting chargeinto said tank under normal conditions, said seal being withdrawn fromsaid trap to effect the discharge of said starting charge into said tankto generate emergency pressure therein. Y

22. In fire extinguishing apparatus, a dis ributing systemcomprisingdistributing devices, a supply of extinguishing liquid connected to saidsystem and comprising a chemical mixing tank charged with extinguishingliquid and cotiperating mixing devices including a starting devicecomprising a starting chamber having a starting charge of chemicaltherein and having a discharge passage formed with a trap andcommunieating with said tank, a restraining device connected with saidstarting device and with said system and comprising an actuating chamberand an actuating transfer pipe connecting said actuating chamber andsaid trap, and a charge of mercury normally forced into said actuatingtransfer pipe and trap to form a restraining mercury seal preventingdischarge of said starting charge into said tank under normalconditions, said seal being withdrawn from said trap into said actuatingchamber under emergency conditions to effect the rapid discharge of saidstarting charge into said tank to generate emergency pressure therein.

23. In fire extinguishing apparatus, a distributing system comprisingdistributing devices, a supply of extinguishingliquid connected to saidsystem. and comprising a,

chemical mixing tank and coiiperating mix-- ing devices including astarting device prising a starting chamber having a starting charge ofchemical therein and having a discharge passage formed with a trap andcommunicating with said tank, and a restraining device connected withsaid starting device and with said system and comprising a charge ofmercury to form a restraining mercury seal preventing-discharge of saidstarting charge into said tank under normal conditions, said seal beingwithdrawn from said trap to efl"ect the discharge of said startingcharge into said tank to generate emergency pressure therein.

24. In automatic fire extinguishing apparatus, a distrihutii'ig systemcharged with non-freezing extinguishing liquid and comprising automaticdistributing devices ineluding automatic sprinkler heads, a supplementalsupply of extinguishing liquid connected to said system through a rentedvalved connection. and comprising a chen1ical mixing tank charged withcarbonate ex; linguishiug liquid and cotiperating mixing devicesincluding a starting device comprising a starting acid chamber linedwith a. neutral resistant coating and having a starting charge of acidtherein and having a discharge passage ,formed with a trap andcommunicating with said tank, a restraining device eotiperating withsaid starting device and comprising an actuating chamber below said trapand an actuating transfer pipe connecting said actuating chamber andsaid trap, an actuating pressure pipeconnecting said actuating chamberand the upper part of said distributing system, a charge of mercurynormally forced into said actuating transfer pipe and tra to form anacid restraining mereury seai of said starting charge of acid into saidtank under normal conditions, said mercury seal being withdrawn fromsaid trap. into said actuating chamber under emergency conditions toeffect the discharge of said acid into said tank to generate emergencypressure therein. i

25. In automatic fire extinguishing appar'aitus, a distributing systemcharged with extinguishing liquid and comprising automatic distributingdevices, a supplemental supply of extinguishing liquid connected to saidsystem and comprising a chemical mixing tank charged with carbonateextinguishing liquid and cotipcrating mixing devices including astarting device comprising a starting acid chamber having a startingcharge of acid therein and having a discharge passage formed with a trapand commumcating with said tank, a restraining de-. vice coiiperatingwith said starting device and comprising anactuating chamber below saidtrap and an actuating transfer pipe connecting said actuating chamberand said trap,

an actuating pressure pipe connecting said preventing dischargeactuating chamber and the upper part of said distributing system, acharge of mercury normally forced into said actuating transfer pipe andtrap to form an acid restraining mercury seal preventing discharge ofsaid starting charge of acid into said tank under normal conditions,said mercury seal being withdrawn from said trap into said actuatingchamber under emergency conditions to effect the discharge of said acidinto said tank to generate emergency pressure therein.

26. In automatic fire extinguishing appa- Mills. a distributing systemcharged with ex tinguishing liquid and comprising automatic distributingdevices, a supplemental supply of extinguishing liquid connected to saidsystem and comprislng a chemical mixing tank charged with carbonateextinguishing liquid and cooperating mixing devices in eluding astarting derice comprising a starting acid chamber having a startingcharge of aeid therein and havin a discharge passage firmed with a trapan communicating with said tank, a restraining device cooperating withsaid starting device and comprisin an actuating chamber below said trapand an actuating transfer pipe connecting said actuating chamber andsaid trap, an actuating pressure pipe connecting said actuating chamberand said distributing system, a charge of mercury normally forced intosa1d actuating transfer pipe and trap to form an acid restrainingmercury seal preventing dis charge of said startin charge of acid intosaid tank under norma conditions, said mercury seal being withdrawn fromsaid trap into said actuating chamber under emergency conditions toefi'cct the discharge of said acid into said tank to generate emergencypressure therein.

27. In automatic fire extinguishing apparatus, a distributing systemcharged with extinguishing liquid and comprisingautomatic distributingdevices, a supplemental supply of extinguishing liquid connected to saidsystem and comprising a chemical mixing tank charged with carbonateextinguishing liquid and coiiperating mixing devices including astarting device comprising a starting acid chamber having a startingcharge of acid thereinv and" having .a discharge passage formed-withatrap and communicating with said tank, a restraining device connectedwith said system and with said starting device andcomprising a charge ofmercury normally forced into said actuating transfer pipe and trap to\form an acid restraining mercury seal preventin discharge of saidstarting charge of acid into said tank under normal conditions, saidmercury seal being withdrawn from said trap into said actuatinn chamberunder,emcrgcncy conditions to effect the discharge of said acid intosaid tank to generate emergency pressure therein.

28. In fire extinguishing apparatus, a distributing system, a supply ofextinguishingliquid connected to an id system and comprising a chemicalmixing tank and coiiperating mixing devices including a devicecomprising a chamber having a charge of pressure producing chemicalth'creii i and having a discharge passage formed with a trap and mummunicating with said tanln and a restraining ldcviceconnected withsaiddevice and with said system andcompnising a bodyof mercury to formarestraining mercury seal preventingv discl'iarge of. said chemicalcharge into said'tank under normal conditions, said seal being Withdrawnfrom said trap to at feet the discharge of said chemical charge intosaid tank to generate pressure therein. 1 29, In fire extinguishingapparatus, a distributing system, asupply of extinguishing liquidconnected to said system and comprising a chemical'mixing tank and(miiperating mixing devices including a device compris- (lug, chamberhaving a charge oi p'reisure ppoduci ng chemical therein and ham a disclarge'passage" formed with a trap and m'maai anng with said tank, and are- "strainingdcvice connected with said device and w th saidsys tcm andcomprising a body of heavy liquid to form a restrannng liquid nectedwith sai seal preventing discharge of said chemical charge into saidtank under normal conditions, said seal being withdrawn from said trapto effect the discharge of said chemical charge into said tank togenerate pressure therein.

30. In fire extinguishing apparatus, a distributing svstem a supplyofextinguishing liquid connected to said system and comprising a chemicalmixin tank and coiiperitting. mixing devicesinclu in a device comprising a chamber having a c large of-acid chemical therein and havin adischarge passage formed with a trap am communicating n h said tank anda restraining device conne d with said device and with said system ndcomprising a body ofmercury to form straining mercury seal preventingdischai'ge of said acid charge into said tank under norma] conditions,said seal bein Withdrawn from said trap to efiiect the disc arge of saidacid charge into said tank to generate pressure therein. 1 a l 31. Infire extinguishing apparatus, a distributing system, a supply ofextinguishing liquid connected to said system and comprising a chemicalmixing tank andcodperating mixing devices including a device comzprisinga chamber having a charge of pres sure producing chemical therein andhaving a discharge passage formed with a trap and communicating withsaid tank, and a restraining device connected with said device and withsaid system and comprising a body of heavy liquid to form a restrainingliquid seal preventing discharge of said chemical charge into said tankunder nor mal conditions and means controlled by said system to withdrawsaid seal from saidtrap to effect the discharge of said chemical chargeinto said tank to generatev pressure therein.

32. In fire extinguishing apparatus, a disv tributing system, a supplyof extinguishing liquid connected to said system and'comprising achemical mixingtank and cotiperat inn mixing devices including a devicecomprising a chamber having a char e of acid chemical therein' andhaving a disc ar e passage formed with a trap and communicating withsaid'tank, nd arestraining device condevice andwith said systom and;comprising a body of mercury to form a restraining mercury sealreventing discharge of said charge into said tank under normalconditions, and means controlled by the pressure conditions or saiddistributing system to withdrawsaid sea] from said. trap to efl'ect thedischarge ofsaid acid charge into said tank to generate pressuretherein. A

33. Inchem'ical fire estinfiaishing, apparatus, a chemical ixing tancharged with pressure produci g, chemical, means to cause tankcomprising a, chemical feeding chamber containing a cotiperatingchemical charge and having a discharge passage communicating with saidtank and cooperating chemical discharging means com rising a governingtransfer pipe connects to said feeding chamber a pressure governingchamber connected to said overning transfer pipe, an overpressure deviceconnected to said governing transfer pipe, a charge of liquid of greaterspecific gravity than said chemical charge, and adapted to move throughsaid transfer governing chamber and her, said prewure governin chamberbeing located above said feeding c amber and producing a pressurecorresponding with the desired pressure in said tank to efi'ect theforcing of said liquid into said pressure governing chamber under thedesired pressure conditions and by displacement to effect the feeding ofchemical into said tank when the tank pressure falls below the desiredpressure.

34. In chemical fire extinguishing apparatus, a chemical mixing tankcharged with pressure producing chemical, means to cause and maintainthe operating pressure in said tank comprising a chemical feedin chambercontaining a cooperating chemica. charge said feeding chamand having adischarge passage communi-.

eating with said tank and cooperating chemical discharging meanscomprising a governing transfer pipe connecte to said feeding chamber, apressure governing chamber connected to said overnlng transfer pipe, acharge of liquirf of greater specific gravity than said chemical chargeand adapted to move through said transfer pipe between said overningchamber and said feeding cham er, said pressure overning chamber beinglocated above sai feeding chamber and producing a pressure correspondingwith'the desired pressure in said tank to effect the forcing of saidliquid into said pressure governing chamber under the desired pressureconditions and by displace ment to efi'ect the feeding of chemical intopipe between said said tank when the tank pressure falls below thedesired pressure.

35. In chemical fire extin uishing apparatus, a chemical mixing tankcharged with pressure producing chemical, means to cause and maintainthe pressure in said tank comprising a chemical feeding chambercontainin a coiiperating chemical charge and a apted to dischar e intosaid tank and cooperating chemica discharge means comprising a charge ofliquid of greater specific gravity than said chemical charge and meansto effect the entry of said liquid into said feeding chamber and bydisplacement to effect the feeding of chemical into said tank when theressure in the apparatus falls below the esired pressure.

36. In chemical fire extinguishing apparatus, a chemical mixing tankcharged with pressure producing chemical, means to cause and maintainthe pressure in said tank comprising a chemical feeding chamber containing .a cooperating acid chemical charge and adapted to discharge intooperating chemical discharging means, c0mprising a charge of mercury andmeans to efl'ect the entry of said mercury into said feeding chamber andby displacement to effect the feeding of chemical into said tank whenthe pressure in the apparatus falls below the desired pressure.

37. In chemical fire extinguishing apparatus, a chemical mixing tankcharged with pressure producing chemical, means to cause and maintainthe pressure in said tank comprising a chemical feeding chambercontainin a coiiperating chemical charge and a apted to discharge intosaid tank and cooperating chemicaldischarging means comprising a chargeof mercury and means actuated by the weight of said mercury to effeetthe feeding of chemical into said tank when the pressure in theapparatus falls below the desired pressure.

JOHN R. HAMILTON.

Witnesses HARRY L. Duncan, Jnssm B. KAY.

said tank and co--

